Color wheel

ABSTRACT

A color wheel including a color filter, a motor, and a fixing element. The motor has a housing and a motor body, and the housing is set to a side of a central axis of the motor body. The color filter is set on the housing of the motor. The motor body is fixed on the fixing element. A holder is formed on the fixing element, and the holder outwardly extends from the fixing element. In addition, the invention also provides a color wheel further including an auxiliary fixing element, which is set on the fixing element and has an outwardly extending holder.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a color wheel and more particularly,this invention relates to a color wheel, which is used in projectiontechnology.

[0003] 2. Description of the Related Art

[0004] Currently, image projection systems have become popular items inthe optoelectronic industry owing to multiple requirements of a systemhaving large display area, small dimension, and thin, light composition.

[0005] The popular projection systems are divided into three typesincluding a liquid crystal display (LCD) type, a liquid crystal onsilicon (LCoS) type, and a digital light processing (DLP) type, whereinthe single-panel LCoS and DLP types advantageously have simplifiedsystems and the following description will take the DLP type as anexample.

[0006] In a DLP projector, a digital control method and a reflectionprinciple are adopted. For a SCR (Sequential Color Recapture) system,light rays are integrated or converged by a light integration rod andthen pass through the color filter of the color wheel, which splits thelight rays. The split light rays are then projected onto a digitalmicro-mirror device (DMD). In this technology, the DMD is used toreplace the liquid crystal panel for representing images in theconventional liquid crystal projector. Since the DMD includes severalmovable micro-mirrors, driving electrodes may control the tilt angle anddeflection time of each movable mirror. Then, the light rays may beprojected to form an image by switching the reflection directions of thelight rays.

[0007] In the DLP projector, different clamping mechanisms are used tofix the color wheel and the light integration rod in the DLP projectorso that the relative position between the color wheel and the lightintegration rod may be controlled. In the projection system, theposition of each optical device through which light rays pass relates tothe overall imaging quality of the DLP projector. So, each opticaldevice has to be precisely positioned. Furthermore, when the color wheelis a SCR color wheel, the alignment precision between the color wheeland the light integration rod is more highly required.

[0008] However, since the conventional color wheel and light integrationrod are fixed to different clamping mechanisms, respectively, therelative position between the color wheel and the light integration rodhas to be adjusted. In addition, the relative position between otheroptical devices and the color wheel and the light integration rod alsohas to be noted. Consequently, it is necessary to spend longer time toartificially adjust the relative position between the color wheel andthe light integration rod as well as that between other optical devicesand the color wheel and light integration rod. Meanwhile, the precisionof correctly adjusting the relative position between the color wheel andthe light integration rod also cannot be easily controlled, and thereproducibility is also poor.

SUMMARY OF THE INVENTION

[0009] In view of the above-mentioned matters, an object of theinvention is to provide a color wheel capable of solving the positioningproblems between a color wheel and an optical element.

[0010] To achieve the above-mentioned object, the invention provides acolor wheel including a color filter, a motor, and a fixing element. Themotor has a housing and a motor body, and the housing is set to a sideof a central axis of the motor body. The color filter is set on thehousing of the motor. The motor body is fixed on the fixing element. Aholder is formed on the fixing element, and the holder outwardly extendsfrom the fixing element. In addition, the invention also provides acolor wheel further including an auxiliary fixing element, which is seton the fixing element and has an outwardly extending holder.

[0011] The color wheel of the invention has the outwardly extendingholder to joint with the optical element. Compared to the prior art,during the aligning step, the relative position between the color wheeland the optical element in this invention needs not to be adjusted usingdifferent clamping mechanisms. Instead, the relative position betweenthe color wheel and the optical element is fixed by using the holder ofthe fixing element or the auxiliary fixing element, and only therelative position between the color wheel and other optical devices ofthe projector needs to be adjusted. Consequently, the invention islaborsaving and timesaving in adjustment. Meanwhile, since nounnecessary clamping mechanism is needed, the dimension of the projectormay be reduced, and the manufacturing cost may be further decreased. Inaddition, the alignment precision and reproducibility are also improved,and the overall quality of the projector is also improved.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIGS. 1A and 1B are schematic side views showing a color wheelaccording to a first embodiment of the invention.

[0013]FIG. 2 schematically illustrates FIG. 1A.

[0014]FIGS. 3A to 3C are cross-sectional views showing the holder takenalong a line A-A of FIG. 1A.

[0015]FIGS. 4A and 4B are schematic side views showing a color wheelaccording to a second embodiment of the invention.

[0016]FIG. 5 schematically illustrates FIG. 4A.

DETAILED DESCRIPTION OF THE INVENTION

[0017] The color wheels according to the preferred embodiments of theinvention will be described with reference to the accompanying drawings.

[0018] Referring to FIGS. 1A and 1B, a color wheel 1 according to afirst embodiment of the invention includes a color filter 11, a motor12, and a fixing element 13. The motor 12 has a housing 121 and a motorbody 122, and the housing 121 is set to a side of a central axis of themotor body 122. The color filter 11 is set on the housing 121 of themotor 12. The motor body 122 is fixed to the fixing element 13. A holder131 is formed on the fixing element 13, and the holder 131 outwardlyextends form the fixing element 13.

[0019] The color filter 11 may be a circular filter or a ring-shapedfilter composed of a red section, a green section, and a blue section.Alternatively, the color filter 11 also may be a circular filter or aring-shaped filter composed of a red section, a green section, a bluesection, and a transparent section. Of course, the color filter 11 alsomay be a ring-shaped transparent plate or a circular transparent plate,on which at least a red film, at least a green film, and at least a bluefilm are formed.

[0020] As shown in FIGS. 1A and 1B, the motor 12 is composed of thehousing 121 and the motor body 122, and the housing 121 is set to a sideof a central axis of the motor body 122. In addition, the color filter11 is set on the housing 121 of the motor 12. Herein, the color filter11 is set on the housing 121 by way of, for example, a fitting, adheringprocess or placing the color filter 11 over the housing 121.

[0021] The motor body 122 is mainly composed of a shell (not shown), amagnetic ring (not shown), laminated steel stack (not shown) and a coil(not shown). When the coil is powered on, the laminated steel stackproduces a magnetic force and a magnetic field. Controlling thepositive/negative property and the intensity of the flowing current maychange the magnetic field in sequence, or produce a rotating magneticfield, to interact with the magnetic ring and thus cause the magneticring to rotate.

[0022] In this embodiment, the motor body 122 is fixed on the fixingelement 13, and the fixing element 13 has the outwardly extending holder131. In this case, the fixing element 13 is a fixing plate for fixingthe color wheel 1 to a projector (not shown).

[0023] In this embodiment, the fixing element 13 and the holder 131 areintegrally formed, as shown in FIG. 1A. In addition, the fixing element13 is connected to or jointed with the holder 131, as shown in FIG. 1B.In this case, the fixing element 13 may be connected to or jointed withthe holder 131 by way of adhering, riveting or screwing.

[0024] Please refer to FIGS. 1A and 1B again. The color wheel 1 in thisembodiment further includes a cap 14 set on the color filter 11 by wayof embedding or adhering. In this case, the cap 14 is used to enlargethe adhesion area between the color filter 11 and the housing 121.

[0025]FIG. 2 schematically illustrates FIG. 1A. In this embodiment, theoptical element 2 is jointed with the holder 131. In this embodiment,the optical element 2 is used to guide light rays or change thetravelling directions of light rays, for example, and to converge lightrays. In addition, the optical element 2 may also homogenize thebrightness distribution of light rays and control the length-to-widthratio of the projected image. In this embodiment, the optical element 2is a light integration rod, which is generally called as a rod, a lighttunnel, a light pipe, etc. in the field of the art. Of course, theoptical element 2 also may be a lens. In this case, the holder 131 maybe jointed with the optical element 2 by way of adhering, riveting, orscrewing. In the way of adhering, an adhesive may be used to adhere theoptical element 2 to the holder 131, wherein the adhesive may be alight-cured adhesive or a heat-cured adhesive. Of course, it is alsopossible to adhere the optical element 2 to the holder 131 by thelight-cured adhesive for positioning them followed by the heat-curedadhesive to reinforce the connection therebetween.

[0026] In addition, the connection portion between the holder 131 andthe optical element 2 has a shape matching with the external shape ofthe optical element 2. The cross section of the holder 131 taken along aline A-A of FIG. 1A may be of an “L” shape (FIG. 3A), a “

” shape (FIG. 3B), a rectangular ring shape (FIG. 3C), or the like.

[0027] In addition, as shown in FIGS. 4A and 4B, a color wheel 3according to a second embodiment of the invention includes a colorfilter 31, a motor 32, a fixing element 33, and an auxiliary fixingelement 34. The motor 32 is composed of a housing 321 and a motor body322, wherein the housing 321 is set to a side of a central axis of themotor body 322. The color filter 31 is set on the housing 321 of themotor 32, and the motor body 322 is fixed on the fixing element 33. Theauxiliary fixing element 34 is set on the fixing element 33 and has anoutwardly extending holder 341.

[0028] Furthermore, as shown in FIGS. 4A and 4B, the color wheel 3 inthis embodiment further includes a cap 35 set on the color filter 31.

[0029] In the second embodiment, in addition to the fixing element 33and the auxiliary fixing element 34, other elements have the samefeatures and functions as those in the first embodiment, and detaileddescriptions thereof will be omitted.

[0030] As shown in FIGS. 4A and 4B, the motor body 322 is fixed to thefixing element 33. Herein, the fixing element 33 is a fixing plate forfixing the color wheel 3 to a projector (not shown). In addition, theauxiliary fixing element 34 is set on the fixing element 33 and has theoutwardly extending holder 341. In this embodiment, the alignment of theauxiliary fixing element 34 and the fixing element 33 are aligned undera microscope. Then, the auxiliary fixing element 34 is fixed to thefixing element 33 by way of adhering followed by solder bonding. Ofcourse, the auxiliary fixing element 34 also may be fixed to the fixingelement 33 by way of adhering, riveting, screwing or solder bonding.

[0031] In this embodiment, the auxiliary fixing element 34 and theholder 341 are integrally formed, as shown in FIG. 4A. In addition, theauxiliary fixing element 34 is fixed to the holder 341, as shown in FIG.4B. Herein, the auxiliary fixing element 34 may be fixed to the holder341 by way of adhering, solder bonding, riveting, or screwing.

[0032]FIG. 5 schematically illustrates FIG. 4A. In addition, the way ofjointing the holder 341 with the optical element 4 and the shape of theholder 341 in the second embodiment are the same as those in the firstembodiment.

[0033] Because the invention utilizes the fixing element of the colorwheel to fix and position the color wheel and the optical element in theprojector, the relative position between the color wheel and otheroptical devices of the projector has to be adjusted, but the relativeposition between the color wheel and the optical element needs not to beadjusted.

[0034] The color wheel of the invention has the outwardly extendingholder to joint with the optical element. Compared to the prior art,during the aligning step, the relative position between the color wheeland the optical element in this invention needs not to be adjusted usingdifferent clamping mechanisms. Instead, the relative position betweenthe color wheel and the optical element is fixed by using the holder ofthe fixing element or the auxiliary fixing element, and only therelative position between the color wheel and other optical devices ofthe projector needs to be adjusted. Consequently, the invention islaborsaving and timesaving in adjustment. Meanwhile, since nounnecessary clamping mechanism is needed, the dimension of the projectormay be reduced, and the manufacturing cost may be further decreased. Inaddition, the alignment precision and reproducibility are also improved,and the overall quality of the projector is also improved.

[0035] While the invention has been described by way of examples and interms of preferred embodiments, it is to be understood that theinvention is not limited to the disclosed embodiments. To the contrary,it is intended to cover various modifications. Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications.

What is claimed is:
 1. A color wheel, comprising: a color filter; amotor having a housing and a motor body, the housing being set to a sideof a central axis of the motor body, and the color filter being set onthe housing of the motor; and a fixing element on which the motor bodyis fixed, and the fixing element having an outwardly extending holder.2. The color wheel according to claim 1, wherein the fixing element andthe holder are integrally formed.
 3. The color wheel according to claim1, wherein the fixing element is jointed with the holder.
 4. The colorwheel according to claim 1, wherein the fixing element is a fixingplate.
 5. The color wheel according to claim 1, further comprising: acap set on the color filter.
 6. A color wheel, comprising: a colorfilter; a motor having a housing and a motor body, the housing being setto a side of a central axis of the motor body, and the color filterbeing set on the housing of the motor; a fixing element on which themotor body is fixed; and an auxiliary fixing element set on the fixingelement and having an outwardly extending holder.
 7. The color wheelaccording to claim 6, wherein the auxiliary fixing element and theholder are integrally formed.
 8. The color wheel according to claim 6,wherein the auxiliary fixing element is jointed with the holder.
 9. Thecolor wheel according to claim 6, wherein the fixing element is a fixingplate.
 10. The color wheel according to claim 6, wherein the fixingelement is jointed with the auxiliary fixing element by way of adheringfollowed by solder bonding.
 11. The color wheel according to claim 6,wherein the fixing element is jointed with the auxiliary fixing elementby way of solder bonding.
 12. The color wheel according to claim 6,wherein the fixing element is jointed with the auxiliary fixing elementby way of adhering.
 13. The color wheel according to claim 6, whereinthe fixing element is jointed with the auxiliary fixing element by wayof riveting.
 14. The color wheel according to claim 6, wherein thefixing element is jointed with the auxiliary fixing element by way ofscrewing.
 15. The color wheel according to claim 6, further comprising:a cap set on the color filter.